The present invention relates generally to the field of battery terminals, and more specifically, the invention relates to a cold formed battery terminal having a male or female insert and a method and apparatus for forming the cold formed terminal.
In general battery terminals are utilized as an interface between a sealed battery container and an external device seeking electrical power. The interface between the terminal may include a female member such as a nut or a male member such as a stud that is embedded in the terminal. In sealed batteries containing liquid electrolyte, the battery terminal must be configured to prevent leakage of electrolyte to ensure the battery will not fail prematurely when called upon. To prevent leakage of electrolyte around a battery terminal it is common to provide a plurality of annular acid rings extending around the head of the battery terminal, which is designed to be embedded in the wall of the container.
Some terminal configurations, such as a marine battery terminal may place the male or female interface offset from the radial rings.
Battery terminals including annular rings on the head are typically formed from lead in a cold or hot forming process. In the hot forming process, a lead alloy is heated until it is in a molten state. The molten lead is then poured into a mold or casting and formed into a partially-finished or finished battery terminal. In the cold forming process a lead slug (typically at room temperature) is subjected to various pressing, punching and machining operations to create the finished battery terminal.
As mentioned above, the hot forming process requires that the lead be heated until it reaches the molten state and then subsequently poured into a multi-part mold until it cools. This is disadvantageous in that melting the lead alloy may create undesirable porosity in the finished battery terminal and is expensive to implement in an environmentally safe manner. The hot forming process can be employed to embed a male or female insert into the terminal while the terminal is being formed. U.S. Pat. No. 5,589,294 entitled “Side Wall Electrical Battery Terminal” and granted on Dec. 31, 1996 and commonly assigned with the instant invention discloses a cold formed terminal having a nut encapsulated in a terminal.
It would be desirable to have a terminal that is cold formed and including both annular rings and a male interface embedded in the terminal. It would also be desirable for the annular rings of the cold formed terminal to be offset from the embedded male or female insert.